| Literature DB >> 26963259 |
Thane A Militz1,2, Jeff Kinch3, Simon Foale4, Paul C Southgate2.
Abstract
A major difficulty in managing wildlife trade is the reliance on trade data (rather than capture data) to monitor exploitation of wild populations. Collected organisms that die or are rejected before a point of sale often go unreported. For the global marine aquarium trade, identifying the loss of collected fish from rejection, prior to export, is a first step in assessing true collection levels. This study takes a detailed look at fish rejections by buyers before export using the Papua New Guinea marine aquarium fishery as a case study. Utilizing collection invoices detailing the species and quantity of fish (Actinopteri and Elasmobranchii) accepted or rejected by the exporting company it was determined that, over a six month period, 24.2% of the total fish catch reported (n = 13,886) was rejected. Of the ten most collected fish families, rejection frequency was highest for the Apogonidae (54.2%), Chaetodontidae (26.3%), and Acanthuridae (18.2%) and lowest for Labridae (6.6%) and Hemiscylliidae (0.7%). The most frequently cited reasons for rejection were fin damage (45.6% of cases), undersized fish (21.8%), and fish deemed too thin (11.1%). Despite fishers receiving feedback on invoices explaining rejections, there was no improvement in rejection frequencies over time (r = -0.33, P = 0.15) with weekly rejection frequencies being highly inconsistent (range: 2.8% to 79.4%; s = 16.3%). These findings suggest that export/import statistics can greatly underestimate collection for the marine aquarium trade as additional factors such as fisher discards, escapees, post-collection mortalities, and unregulated domestic trade would further contribute to this disparity.Entities:
Mesh:
Year: 2016 PMID: 26963259 PMCID: PMC4786313 DOI: 10.1371/journal.pone.0151624
Source DB: PubMed Journal: PLoS One ISSN: 1932-6203 Impact factor: 3.240
Reasons given for fish rejections and the grouping terms used in this study.
| As Grouped in this Study | Reported Reasons on Invoice |
|---|---|
| Too thin | Too thin |
| Undersized | Too small |
| Too fat | Too fat |
| Oversized | Too large |
| Not ordered | Wrongly Identified |
| Not ordered | |
| Body damage | Bruised |
| Tissue damage | |
| Removed scales | |
| Bulging eye | |
| Fin damage | Torn fin |
| Dead | Dead |
Fig 1Total catch for the most collected fish families (A) and species (B) divided into those fish accepted and rejected by the exporting company.
The percentage of catch rejected for a given family or species is presented as superscripts.
Fig 2Reasons for rejecting individual fish as a percentage of explained rejections.
Primary causes for rejection of fish from the five most collected families.
| Family | Primary Causes for Rejection (% of explained rejections) |
|---|---|
| Pomacentridae | Undersized (41.5%) |
| Fin damage (38.7%) | |
| Apogonidae | Too thin (46.6%) |
| Undersized (22.8%) | |
| Chaetodontidae | Fin damage (78.0%) |
| Undersized (14.4%) | |
| Acanthuridae | Fin damage (40.8%) |
| Oversized (38.5%) | |
| Labridae | Fin damage (48.6%) |
| Not ordered (18.9%) |
Fig 3Total catch of fish by each community divided into those fish accepted and rejected by the exporting company.
The percentage of total catch rejected is presented as superscripts. (A) Presents all data during the study period. (B) Data with one week of fishing at Roku omitted.
Fig 4Proportion of total catch rejected (square root transformed) plotted against (A) total catch and (B) catch of apogonids and chaetodontids over the study period for individual fishers.